Circuit breaker panels are used to protect electrical circuitry from damage due to an overcurrent condition, such as an overload, a relatively high-level short circuit, or a ground fault condition. To perform that function, circuit breaker panels include circuit breakers that typically contain a switch unit and a trip unit. The switch unit is coupled to the electrical circuitry (i.e., lines and loads) such that it can open or close the electrical path of the electrical circuitry. The switch unit includes a pair of separable contacts per phase, a pivoting contact arm per phase, an operating mechanism, and an operating handle.
In the overcurrent condition, all the pairs of separable contacts are disengaged or tripped, opening the electrical circuitry and moving the operating handle to a tripped position. When the overcurrent condition is no longer present, the circuit breaker can be reset using the operating handle such that all the pairs of separable contacts are engaged, closing the electrical circuitry.
In addition to manual overcurrent protection via the operating handle, automatic overcurrent protection is also provided via the trip unit. The trip unit, coupled to the switch unit, senses the electrical circuitry for the overcurrent condition and automatically trips the circuit breaker. When the overcurrent condition is sensed, a tripping mechanism included in the trip unit actuates the operating mechanism, thereby disengaging the first contact from the second contact for each phase. Typically, the operating handle is coupled to the operating mechanism such that when the tripping mechanism actuates the operating mechanism to separate the contacts, the operating handle also moves to the tripped position.
Switchgear and switchboard are general terms used to refer to electrical equipment including metal enclosures that house switching and interrupting devices such as fuses, circuit breakers and relays, along with associated control, instrumentation and metering devices. The enclosures also typically include devices such as bus bars, inner connections and supporting structures (referred to generally herein as “panels”) used for the distribution of electrical power. Such electrical equipment is typically maintained in a utility area of a building such as the basement of a residence or in a utility closet of a commercial establishment, or it can be maintained outside of such facilities and exposed to environmental weather conditions.
Typically, hinged doors or covers are provided on the front of the switchgear or switchboard sections to limit access to the devices contained therein. The doors and enclosures protect the equipment and serve as a safety precaution to protect people from the high-energy circuits within. However, the only indication that a circuit break has tripped may be that the operating handle (e.g., behind a closed door) has moved to the tripped position. Since the electrical equipment may not be in a prominent area, the residents or building occupants may not immediately notice that a circuit breaker has tripped. This can be problematic. For example, a food storage freezer may be on a branch circuit shared with an electrical outlet. If the circuit breaker for the branch circuit is tripped, the smell of rotting food several days later may be the first indication a resident notices that the food storage freezer has not had power. Therefore, there is a need for systems and methods to provide notification that a circuit breaker has tripped.